But there's still a lot of make-or-break work to do before the season opens. Here are 10 questions that have to be answered:

1. Who will be the pass-rusher to replace defensive end Cliff Avril, now with Seattle?

This is easily the biggest void that has to be addressed. You can't win in the NFL without pressuring the quarterback.

The Lions added
Jason Jones from the
Seahawks, but he's more of a power guy than a speed rusher off the edge.

Detroit, which finished tied for 20th in the league in sacks last season, could use its No. 5 pick overall in the draft on BYU defensive end Ziggy Ansah, Oregon outside linebacker
Dion Jordan or LSU linebacker/end
Barkevious Mingo.

2. Who will be the starting left tackle to replace retired Jeff Backus?

Based on the current roster, it would be
Riley Reiff, last year's first-round draft pick out of Iowa.

But the Lions also could go for a top-rated tackle in the draft such as Texas A&M's
Luke Joeckel or Central Michigan's Eric Fisher. Both are better long-term prospects than Reiff, who went 23rd overall.

3. Who will be the starting right tackle to replace Gosder Cherilus, now with Indianapolis?

If the Lions draft one of the offensive tackles then Reiff probably moves over to the right side.

The other options are
Corey Hilliard, who didn't play in a game last year but is entering his seventh NFL season, and
Jason Fox, an often-injured fourth-round draft pick in 2010 out of Miami (Fla.)

The top choice right now is probably
Bill Nagy, claimed off waivers from Dallas last year and coming off a broken ankle. Other possibilities include
Rodney Austin, an undrafted free agent from Elon University, or
Dylan Gandy, who has 19 starts in his seven NFL seasons.

Reiff also could move inside if the Lions draft a tackle and the options at guard aren't working out.

5. Who will be the starting outside linebacker for Justin Durant, now with Dallas?

If the Lions don't draft a linebacker-type such as Jordan, Mingo or Georgia's
Jarvis Jones, the in-house candidates start with
Ashlee Palmer, who has been one of the team's top special-teams players.

The Lions could take their much-ridiculed secondary to an even higher level by drafting Alabama cornerback
Dee Milliner in the first round.

But they're more likely to lean to someone at a value position -- pass-rusher or offensive tackle -- with such an early pick.

The returning candidates at corner are
Bill Bentley, a third-round pick who missed much of his rookie year because of a shoulder injury;
Jonte Green, a sixth-round pick who exceeded expectations in his first year; eight-year NFL veteran
Ron Bartell, who started the final game of the season; or
Chris Greenwood, a fifth-round pick who missed all of his rookie year following abdominal surgery.

They signed
Blake Clingan, who hasn't punted in a game since his senior year at Central Florida in 2010. It's not just a question of whether he's talented enough, but also whether he can handle the pressure in the NFL.

Running back
Joique Bell (kick returns) and receiver
Mike Thomas (punt returns) split the duties when Logan got demoted for the final game. There's also been speculation the Lions might consider using Bush at times. Two players coming off injuries -- receivers
Ryan Broyles and
Patrick Edwards -- also have return experience.

It's quite possible, however, that the role will be filled through a free agent still to be added or a draft pick.